We will investigate biosynthesis by monitoring incorporation of radiolabelled precursors into LH by dispersed rat anterior pituitary cells. Newly synthesized LH will be isolated by immunoprecipitation with specific antibodies. The effects of estrogen and progesterone on LH biosynthesis will be determined in this system. Also the relationships between synthesis and release will be studied in an attempt to determine if these two steps of secretion are tightly coupled. The effect of GnRH on the size of LH will be monitored by comparing LH synthesized in the presence of GnRH with that synthesized in the absence of GnRH.